The Invention is based on a protective hood for a right-angle grinder.
From European Patent Disclosure EP 0 537 198 B1, a protective hood is known that has a tightening device for tight fastening to the clamping neck of a power tool, in particular a right-angle grinder. The tightening device is mounted on a tightening band, which is firmly connected to the protective hood. The ends of the tightening band are each embodied as eyelets. The tightening device comprises a tightening lever and a transmission member, and both the transmission member the tightening lever are each connected to one end of the tightening band in such a way that they are each pivotable about a pivot axis embodied by the eyelets. The transmission member is also supported pivotably in the tightening lever about a further pivot axis, and the three pivot axes are parallel to one another and do not coincide. As a result, in tightening and loosening the tightening device functions like a toggle lever device. By means of such a design, it is possible to replace the protective hood on the clamping neck of the right-angle grinder without using additional tools, such as a screwdriver.
The protective hood for a right-angle grinder has the advantage over the prior art of a more economical design, and the advantage of the aforementioned prior art, that is, that the protective hood for a right-angle grinder can be removed from the right-angle grinder without using an additional tool, is still possible.
Because the second tightening element is embodied as a spring, it is possible to compensate for production variations in the components of the protective hood for a right-angle grinder. This is made possible to a certain extent by the elasticity of the spring. It is furthermore possible for the tightening band to be bent open or compressed to a greater extent that was possible in the prior art, since the spring used as the second tightening element does not constantly engage the end embodied as the second axis but rather engages it only in the prestressed state and in the tightened state. The protective hood for a right-angle grinder is then firmly connected to a right-angle grinder.
It is advantageous to embody the spring With an undulating form in a direction perpendicular to one of the axes. Production variations in the two ends of the tightening band, which are embodied as eyelets, and in the tightening band can then be well compensated for. If the spring is of wire, then it can be produced especially easily, and compared with a leaflike spring, there is a saving in terms of weight.
Advantageously, the wire is bent such that its ends face one another and are parallel to the second axis and assume the contour of a flat rectangular body. This increases the certainty that the spring will not slip out of the tightening lever.
It is furthermore advantageous if the undulating shape of the spring has different amplitudes, and if the spring has a shape that is symmetrical to a plane of symmetry that is vertical to the second axis. Such springs are simple to produce and because of their symmetry they cooperate especially well with the other elements of the tightening device.
It is also advantageous if the first end of the tightening lever has an eccentric leg, which is embodied eccentrically to the first axis and is associated with a first shoulder of the tightening band in the region of the first eyelet, with which shoulder it can be brought into a contact position to limit the opening angle and as security against unintentionally emerging from the first eyelet.
It is advantageous as well if a lug protrudes past the inside face of the tightening band and/or if a convex curvature is provided on the inside face of the tightening band. On the one hand, this assures axial security against loss of the protective hood for a right-angle grinder, since the lug can engage a groove on the clamping neck. On the other, the convex curvature prevents torsion of the protective hood for a right-angle grinder relative to the clamping neck in the azimuth direction relative to the pivot axis of the work spindle.
It is especially advantageous if the lug and the convex curvature are disposed one above the other in a direction parallel to the first axis. As a result, they can be produced very simply and in only a single operation, for instance by stamping.
Further advantageous features of the invention will become apparent from the dependent claims.